1. Field of the Invention
This invention relates to a method and system for aiding an operator in executing step by step procedures during the operation of a complex process facility. More specifically, it relates to simultaneous execution of multiple procedures, some or all of which can be automatically executed, and particularly, to maintaining operator supervisory control over each of the procedures under such circumstances.
2. Background Information
Operation of a complex process facility requires the assimilation of a large amount of data and evaluation of the status of the process and the various component systems from those data, and informed, decisive action based upon such evaluation. While much of the operation of the modern complex process facility is automatically controlled, overall supervision of the facility is always the responsibility of a human operator.
Typically, formal written plant operating procedures under either normal or emergency conditions are developed by experienced specialists. Such "paper" procedures have been used for many years particularly in facilities such as nuclear power plants. Recently, interactive computer-based systems for aiding the operator in the execution of complex operating procedures have been developed. For instance, U.S. Pat. No. 4,803,039 discloses such a system in which the sequential steps of a procedure are presented to the operator on a display screen. The system automatically monitors the appropriate parameters relevant to the procedure steps. Where conditions required by certain steps are not satisfied, alternatives are offered to the operator. In either case, a response is required from the operator before the system advances to either the next step or a step in another procedure commanded by the operator. U.S. Pat. No. 4,815,014 describes a related system that requires verification that an operator action has, in fact, been taken before it will advance to the next step in the procedure. The operator, however, may override the requirement for such verification. The interactive systems described to this point were hard coded therefore requiring the writing of new code and verification of all of the software when any changes were to be made, including altering of reference values of the various parameters. U.S. Pat. No. 5,553,304 overcomes this particular problem by describing the use of a relational database to generate and store equations representing the various sequential steps in the procedures. With such a system, changes can be made in the pertinent parameter values and even in the procedures themselves without the necessity to generate new code and verifying that code.
However, the interactive computer-based systems for assisting in the execution of complex process procedures currently require manual input by an operator to advance to a next step. They also only provide the ability to have one procedure active at a time. If the operator accepts a recommendation to transfer to another procedure, the exited procedure becomes inactive.
With the complexity of process facilities, such as especially nuclear power plants, increasing, there is a particular need for an improved system and method for accurately and expeditiously executing procedures in a complex process facility.
There is a particular need for such a method and system which permits multiple procedures to be active simultaneously.
This creates an additional need for a method and system which allows for the procedures to be executed automatically while maintaining operator supervisory control over the procedures.